Problems mount for NASA's Ares rocket

时间：2017-05-02 07:00:07166网络整理admin

By David Shiga Could a moderate breeze spell doom for the rocket NASA is developing to launch astronauts into orbit after the space shuttle’s retirement? On 26 October, the Orlando Sentinel newspaper obtained NASA computer simulations that showed wind speeds of just over 20 kilometres per hour could blow the Ares I rocket into its launch tower during lift-off. But later that week, Steve Cook, manager of the Ares project at NASA’s Marshall Space Flight Center in Huntsville, Alabama, said much more powerful winds would be needed to endanger the rocket. “The wind condition that we’re concerned about is a southerly wind at 34 knots [63 km/h], and our estimate [is] that would only happen about 0.3% of the time,” Cook said in a teleconference with reporters. Problems could be avoided simply by not launching on the rare days when the wind got that strong, Cook said. He added that Ares I is actually much more robust against winds than the space shuttle, which he says has a wind limit of 19 knots (35 km/h). Multiple design problems have plagued Ares I, including a tendency to vibrate excessively. One NASA engineer, who has participated in studies of Ares I performance, told New Scientist the rocket’s design needs a complete rethink: “You might as well change gears and work on a design that is going to be successful.” Ares I is likely to be reviewed after the US election. The engineer says many people within NASA are pessimistic: “They don’t think the project will survive as it is.” But NASA has consistently downplayed the criticisms. “I think we are beset by quite a number of commentators who really don’t understand what’s involved in an engineering development programme,” agency chief Mike Griffin said at the International Astronautical Congress in Glasgow, Scotland, earlier this month. “The development of our Ares and Orion crew vehicles, despite what you read on internet blogs, is actually going quite well.” More on these topics: